The call comes after at least 50 men in civilian clothes, who were later identified as police and security officers, raided the Cairo office of the Egyptian Centre for Economic and Social Rights on Wednesday.According to the UN Office of the High Commissioner for Human Rights (OHCHR), six members of the non-governmental organization (NGO) were arrested and allegedly beaten, and three laptops, files and documents were seized.“The raiding of a human rights NGO and the arrest of six of its members in Cairo on Wednesday night marks a worrying escalation in the harassment and intimidation of civil society in Egypt,” Ravina Shamdasani, spokesperson for OHCHR, told reporters in Geneva.She said that five of the individuals arrested were released after some nine hours in custody, during which time they were reportedly mistreated. One prominent human rights defender, Mohamed Adel Fahmi, a member of the April 6th movement, remains in detention, his whereabouts unknown.“We call on Egyptian authorities to immediately release all individuals who have been detained in relation to their work as human rights defenders,” said Ms. Shamdasani. “Intimidation of political opponents, activists and human rights defenders for peaceful exercise of their fundamental rights to freedom of expression and association must be halted.“An independent and impartial investigation needs to be conducted into the raid on the Egyptian Centre for Economic and Social Rights,” she added.Egypt has been undergoing a democratic transition following the toppling of President Hosni Mubarak two years ago in the wake of mass protests. This past July, renewed protests, in which dozens of people were killed and wounded, led to the Egyptian military deposing President Mohamed Morsy. The Constitution was then suspended and an interim government set up.